频率选择性衰落信道下的STBC调制识别技术  

Blind Modulation Identification of STBC Over Frequency-Selective Fading Channels

作　　者：于柯远 闫文君 金堃 刘昭 YU Ke-yuan;YAN Wen-jun;JIN Kun;LIU Zhao(China Naval Aeronautical University,Yantai Shandong 264001,China;92429 Army,Qingdao Shandong 266100,China)

机构地区：[1]海军航空大学,山东烟台264001 [2]92429部队,山东青岛266100

出　　处：《计算机仿真》2021年第6期154-159,共6页Computer Simulation

基　　金：国家自然科学基金(91538201);泰山学者工程专项经费(No.ts201511020)。

摘　　要：针对频率选择性衰落信道下空时分组码(Space Time Block Codes, STBC)信号的调制识别问题,改进了一种基于四阶时延矩的调制识别算法。研究的调制方式主要包括BPSK,QPSK,8PSK和16QAM四种典型调制星座,在单接收天线条件下,首先对STBC信号及频率选择性衰落信道进行建模,计算接收端STBC信号四阶时延矩的理论值;然后采用阈值检测方法,将四阶时延矩的估计值同理论值的阈值区间对比,从而自动判别出信号的调制方式。推导和仿真结果表明,上述算法不需要噪声、空时分组码类型等先验信息,在较低信噪比条件下,对四种调制方式也具有良好的识别性能,且对频偏、多普勒频移和时延的鲁棒性能好,计算量较低,具有较高的实用价值。A modulation mode recognition algorithm is proposed in the paper based on fourth-order lag product for STBC signal modulation identification problem. The modulation methods studied in this paper mainly include four typical modulation constellation BPSK, QPSK, 8 PSK and 16 QAM. Under the condition of single receiving antenna, the STBC signal and frequency selective fading channel were firstly modeled to calculate the theoretical value of the fourth-order time delay moment of STBC signal at the receiving end. Then the threshold detection method was used to compare the estimated value of the fourth-order delay moment with the threshold interval of the theoretical value, so as to automatically identify the modulation mode of the signal. The results of derivation and simulation show that the algorithm does not need prior information, such as noise, space-time block code type, etc. It also has good recognition performance for the four modulation modes under the condition of low signal-to-noise ratio, good robustness performance for frequency deviation, Doppler frequency shift and time delay.

关 键 词：空时分组码 四阶时延矩 调制识别 频率选择性衰落 

分 类 号：TN911.7[电子电信—通信与信息系统]